JP2005068611A - Coating base paper for coated paper for web offset printing and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an easily producible coating base paper for the production of a coated paper for web offset printing having excellent effect for suppressing the generation of creases in the drying after printing and provide a method for producing the base paper. <P>SOLUTION: The coating base paper for the production of a coated paper for web offset printing having one or more coating layers on one or both surfaces has a longitudinal/lateral strength ratio of 1.1-1.3. The method for the production of the coating base paper for the coated paper for web offset printing comprises the single use of a J/W ratio controlling means or a combination of the controlling means with a shaking controlling means. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a coated base paper used for coated paper for rotary offset printing and a method for producing the same. More specifically, by dispersing the direction of shrinkage of pulp fibers during drying after offset rotary printing, the coating used for coated paper for offset rotary printing is excellent in suppressing the generation of wrinkles that occur during drying after printing. The present invention relates to a base paper and a manufacturing method thereof.

  In recent years, offset printing has become increasingly faster and more simultaneous with multicolor printing in line with increasing demand for printed materials and labor savings. In addition, with the advancement of printing presses and inks, higher-quality printing effects have been achieved on printing paper. A quality characteristic with In particular, when the coated paper is subjected to offset rotary printing, a phenomenon peculiar to this method called “hijiwa” may occur. Hijiwa is a wrinkle generated in the direction of paper flow that occurs when the ink on the paper is forcibly dried at a high temperature after offset rotary printing on the coated paper, and causes the appearance of the printed matter to be impaired. As a cause of the occurrence, it is generally known that a difference in shrinkage between the image area and the non-image area at the time of drying is related (for example, see Patent Document 1).

  Of the printed matter, the image area is covered with an ink film, and moisture in the paper is less likely to scatter compared to the non-image area. For this reason, at the time of forced drying after offset rotary printing, the non-image area starts to contract earlier than the image area, and wrinkles occur due to the difference in the amount of contraction between the two. Factors that affect the generation of wrinkles include fiber orientation and moisture in the coated paper.

  In general, it is said that the drying shrinkage of fibers is much larger in the width direction than in the length direction. For this reason, when the fibers shrink in the drying process after printing, if the fibers are aligned, the movement tends to affect the dimensional change of the entire paper. Therefore, the amount of shrinkage at the time of forced drying after printing becomes large, and wrinkles are deteriorated. Therefore, it is desirable that the fiber orientation is low in order to eliminate creases. However, it is difficult to make paper by changing the fiber orientation greatly in paper making with an actual machine. In the past, efforts have been made to match the fiber orientation angle with the paper flow direction.

  In addition, if the amount of shrinkage during heating of the coated paper itself can be reduced or eliminated, the difference in the amount of shrinkage between the image area and the non-image area is also reduced or eliminated, that is, wrinkles are reduced or eliminated. For this purpose, it is conceivable as one means to suppress volatile moisture during heating of the coated paper. According to this method, generation of wrinkles is suppressed. The moisture of the coated paper can be set to some extent at the time of manufacture, and it is possible to eliminate wrinkles by drying to the limit. However, in this case, the effect of high gloss and high smoothing by the calendar process becomes extremely thin and the product value is lost, and wrinkles and curls due to moisture absorption from moisture in the air are concerned. Further, when strong drying is actually performed, there is a problem that drying energy is required and the manufacturing cost is increased.

Conventionally, a method for limiting microwave transmission strength, water immersion elongation, air permeability, and paper thickness (for example, see Patent Document 2), and a method for limiting internal interlayer strength and moisture (for example, see Patent Document 3). ), A method of applying a polyalkylene glycol to a base paper (see, for example, Patent Document 4), a method of using a base paper obtained by applying and drying polyvinyl alcohol with a saponification degree and a dry coating weight defined (for example, However, in all cases, it is not sufficient to suppress elbows and blisters, and there are many problems such as equipment and cost in practical use.
JP 58-186700 A JP-A-6-57686 JP-A-9-291696 JP 2001-180100 A JP-A-11-350391

  An object of the present invention is to provide a coated base paper used for coated paper for offset rotary printing, which can suppress the generation of wrinkles generated in the drying process after offset rotary printing in view of the above situation, and the production thereof. A method is provided.

  As a result of diligent research in view of the above, the present inventors have invented a coated base paper used for the offset rotary printing coated paper of the present invention and a method for producing the same.

  That is, the coated base paper used for the offset rotary printing coated paper in the present invention is the coated base paper used for the offset rotary printing coated paper provided with at least one coating layer on one side or both sides. The aspect ratio of the tensile strength of the base paper is 1.1 to 1.3.

  In the above invention, the coated base paper is preferably made of forest certified material LBKP as a pulp raw material.

  Moreover, in the said invention, it is preferable that a coating base paper uses a waste paper pulp as a pulp raw material.

  In addition, the method for producing a coated base paper used for the offset rotary printing coated paper in the above invention is characterized by being produced by a J / W ratio control means alone or in combination with a shaking control means. It is.

  Hereinafter, the coated base paper used for the coated paper for rotary offset printing in the present invention and the production method thereof will be described in detail.

  In the present invention, the aspect ratio of the tensile strength of a coated base paper (hereinafter sometimes simply referred to as base paper) used for offset rotary printing coated paper is the length of the base paper defined in JIS P-8113. The tensile strength of the base paper in the direction and the lateral direction is measured, and is defined by the following general formula 1.

(Equation 1)
Aspect ratio = Tensile strength in the longitudinal direction / Tensile strength in the transverse direction (General formula 1)

  The ratio of the tensile strength in the vertical direction and the tensile strength in the horizontal direction of the base paper is set to 1.1 to 1.3. As a result, since fiber shrinkage is large in the width direction of the fiber after drying after printing, by reducing the fiber aspect ratio, the direction of fiber shrinkage is dispersed and shrinkage in the width direction of the base paper is reduced. It is considered that generation of wrinkles at the time of offset rotary printing is also suppressed in coated paper in which a base paper is provided with a coating layer containing a pigment and an adhesive.

  The aspect ratio in the present invention is generally calculated using the tensile strength of the base paper, but can also be measured using the anisotropy of the ultrasonic transmission speed as a simple method. In this measurement method, the speed at which the ultrasonic wave passes between fibers is slower than the speed at which it passes through the fiber, and the fastest and slowest directions are measured and the ratio of these is substituted. You can also.

  In the present invention, when the aspect ratio of the tensile strength of the coated base paper is less than 1.1, it is close to 1, which is an ideal aspect ratio in which the fibers themselves are lined up completely at random. It is very difficult to reduce the aspect ratio to less than 1.1 with a conventional paper machine in terms of productivity and formation.

  On the other hand, when the aspect ratio of the tensile strength of the coated base paper exceeds 1.3, a certain degree of dispersion proceeds from the aspect of fiber shrinkage, but the shrinkage of the fibers distributed in the longitudinal direction increases, so the coated paper It is impossible to suppress the generation of wrinkles during offset rotary printing.

  In the present invention, examples of the wood pulp used for papermaking include paperboard pulp in addition to NBKP, LBKP, NBSP, LBSP, GP, TMP, and the like. Moreover, in virgin pulp, it is desirable to use LBKP, a forest certified material. In use, they are used by mixing them at a ratio according to the purpose, but it is desirable that the forest certified material LBKP is mixed at 30% by mass or more of the virgin pulp fiber.

  The forest certification material referred to in the present invention is the “Earth Summit” held in 1992, and the “Forest Principles Statement” was adopted. It is a material that has been harvested from a forest that has been certified by a third-party organization in accordance with a two-way approach to conserve production and the environment of the forest. Typical third-party certification is called “FSC (Forest Stewardship Council) certification”, which is FSC certification material. In the present invention, other certification bodies such as “PEFC” and “SGEC” are used. I do n’t mind the certification body. Furthermore, in the present invention, it is desirable to use forest certification material LBKP.

  Forest certified timber is produced in managed forests, has high uniformity when made into pulp, and has a small fiber length / fiber width ratio. Yes, high blending is preferred for coated paper wrinkles. However, in the present situation, it is difficult to obtain, and the blending rate is limited in that respect. Considering these points, the blending ratio of the forest certification material LBKP depends on the required quality of the coated paper for rotary offset printing, but is preferably 30% by mass or more of the virgin pulp used in the present invention.

  In addition, as the raw paper pulp used in the present invention, the white paper, ruled white, cream white, card, special white, medium white, imitation, as shown in the used paper standard quality specification table of the used paper recycling promotion center , Fair white, Kent, white art, special upper limit, another upper limit, newspaper, magazine and so on. Specific examples include non-coating computer recording paper which is information-related recording paper, printer recording paper such as thermal paper and pressure sensitive paper, and OA waste paper such as PPC recording paper, art paper, coated paper, fine coated paper, Coated paper such as matte paper, high quality paper, color quality, notebook, notepaper, wrapping paper, fancy paper, medium quality paper, newsprint, reprint paper, supermarket paper, imitation paper, pure white roll paper, milk carton, etc. Chemical pulp paper, high-yield pulp-containing paper, and the like are used as paper such as non-coated paper and used paper, but it is not particularly limited regardless of printing, copying, printing, or non-printing.

  Since waste paper pulp has a keratinized fiber surface, heat shrinkage is smaller than that of virgin pulp, and therefore high blending is preferred for coated paper elbows. However, the fiber has a high content of fine fibers, and the blending rate is limited in that respect. Considering these points, the blending ratio of waste paper pulp depends on the required quality of the coated paper for offset rotary printing, but is preferably 35% by mass or more in the present invention.

  The filler used when making the base paper of the present invention is not particularly limited, and known calcium carbonates such as heavy calcium carbonate and light calcium carbonate, inorganic fillers such as talc, clay and kaolin, and organic fillers are used. it can. Of course, several kinds of calcium carbonate and various fillers can be used in combination.

  The internally added sizing agent used for making the base paper of the present invention is not particularly limited, and is generally used for acidic paper making sizing agents such as rosin sizing agents and petroleum resin sizing agents, and alkenyl anhydride succinic acid. Neutral papermaking sizing agents such as acids, alkyl ketene dimers, and neutral rosin sizing agents can be used.

  In addition to the above, in the paper material, other various anionic, nonionic, cationic, or amphoteric paper strength improvers that have been used in the past are used within a range that does not impair the desired effect of the present invention. An internal additive is appropriately selected and used as necessary. For example, various starches, and one or more of polyacrylamide, polyethyleneimine, polyamine, polyamide / polyamine, urea formalin resin, melamine formalin resin, vegetable gum, polyvinyl alcohol, latex, polyethylene oxide, polyamide resin are appropriately used. Used in combination.

  In addition, it is also possible to appropriately add internal additives for papermaking such as dyes, pH adjusters, antifoaming agents, pitch control agents, slime control agents, etc., depending on the purpose.

  On the other hand, the surface sizing agent is applied with a water-soluble binder in a size press apparatus installed after the pre-dryer, coated on paper, and dried with an after-dryer to develop size characteristics. In general, coating has been performed using a known method such as a size press method, a spray method, or a calendar sizing method, but in the present invention, it can be added as appropriate.

  Examples of the water-soluble binder used in the above apparatus include polyvinyl alcohol, silanol-modified polyvinyl alcohol, vinyl acetate, oxidized starch, phosphate esterified starch, etherified starch, carboxymethylcellulose, hydroxyethylcellulose and other cellulose derivatives, casein, and gelatin. , Soybean protein, silyl modified polyvinyl alcohol, etc .; maleic anhydride resin, styrene-butadiene copolymer, conjugated diene copolymer latex such as methyl methacrylate-butadiene copolymer; vinyl heavy polymer such as ethylene vinyl acetate copolymer Polymer latex modified with functional group-containing monomers such as carboxyl groups of these various polymers; Water-based adhesives such as thermosetting synthetic resin systems such as melamine resin and urea resin; Methacrylate, polyurethane resin, unsaturated polyester resin, vinyl chloride - vinyl acetate copolymer, polyvinyl butyral, a synthetic resin adhesive such as alkyd resins can be used in one or more. In addition, the use of a known natural or synthetic resin adhesive is not particularly limited.

  Further, as the surface sizing agent, in general, styrene-maleic acid copolymer, vinyl acetate-maleic acid copolymer, alkyl ketene dimer, styrene-acrylic copolymer, anionic system called ion complex A composite material of a copolymer and a cationic copolymer, an olefin-maleic acid copolymer, and the like are known.

  In addition to the size press solution, other additives include pH adjusters, thickeners, fluidity improvers, antifoaming agents, antifoaming agents, mold release agents, foaming agents, penetrants, coloring dyes, and coloring pigments. Of course, an optical brightener, an ultraviolet absorber, an antiseptic, an antifungal agent, an antioxidant, an inorganic conductive agent such as sodium chloride and potassium chloride, an organic conductive agent, and the like can be appropriately blended.

  In the papermaking method of the base paper of the present invention, the paper machine is a paper machine known in the paper industry such as a long paper machine, a twin wire paper machine, an on-top paper machine, a combination paper machine, a round paper machine, and a Yankee paper machine. Can be used.

  Next, this inventor examined the manufacturing method of the coating base paper used for the coated paper for offset printing.

  In order to control the aspect ratio of the tensile strength of the base paper, the ratio of the wire speed to the jet flow speed of the pulp slurry (J / W ratio), the dewatering pattern on the wire, and the shape of the paper machine wire part can be adjusted. This can be done by providing a king device.

  One method is to control the aspect ratio of the tensile strength of the base paper while changing the J / W ratio to maintain the base paper formation. Shaking may not be applicable to high-speed paper machines, and the aspect ratio control method of tensile strength by J / W ratio control means alone is an effective method, but has a drawback that the range of the optimum value is narrow.

  Regarding shaking, TAPPI (1966) Vol. 49, no. 10 discloses the relationship between formation of a long paper machine and shaking strength. When the shaking strength is 30 or more, it can be aggregated into one relational expression, and a remarkable improvement in formation is obtained at 30 to 60, and the improvement of formation is reduced at 60 to 90. It is disclosed that improvement is not seen, and if it is less than 30, the relationship between shaking strength and formation cannot be explained. The shaking strength according to this document is defined by the following general formula 2.

(Equation 2)
I = F ² × A / S (General formula 2)
I: SHAKE INTENSITY [times ² / min]
F: Frequency [times / minute]
A: Amplitude [inch]
S: Paper machine speed [feet / min]
In addition, although this definition uses inches and feet, in the present invention, it is assumed that the calculation is performed by converting into inches and feet in accordance with the practice of the industry.

  However, the above document has no description or suggestion regarding the relationship between the shaking strength and the aspect ratio of the base paper, and the object of the present invention is not the texture and the surface quality described in the above paper, but the base paper. Aspect ratio of tensile strength. Therefore, as a result of appropriately examining the aspect ratio of the shaking strength and the tensile strength, if the shaking strength is between 20 and 80 in the present invention, an appropriate coating can be applied to a relatively wide range of J / W ratio. It has been found that it is possible to generate an aspect ratio of the tensile strength of the base paper, and as a result, to provide a base paper for use in a coated paper for offset printing that is excellent in the ability to relax wrinkles.

  Here, when the shaking strength is less than 20, the amount of work sufficient to vibrate the pulp slurry discharged onto the wire cannot be reached, and a sufficient aspect ratio cannot be obtained with the coated base paper. On the other hand, if the shaking strength exceeds 80, not only is the energy of the machine large, it is not efficient, but also the paper formation is worsened.

  The coated base paper can be finished using a calendar device such as a machine calendar, a thermal calendar, a super calendar, or a soft calendar, if necessary.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples. In addition, unless otherwise indicated, the part and% in an example show a mass part and mass%, respectively.

  Prior to the examples and comparative examples, the composition of the base paper used for the offset printing coated paper is as follows.

<Base paper formulation 1>
Base paper formulation; LBKP (freeness: 320 ml, csf) 85 parts
NBKP (freeness: 480 ml, csf) 15 parts calcium carbonate (Okutama Kogyo Co., Ltd .; TP-121) 15 parts AKD sizing agent (Arakawa Chemical Co., Ltd .; SPK-903) 0.03 parts Aluminum sulfate 0 .6 parts amphoteric starch (NSC, Japan; Cato 3210) 1 part Yield improver (made by Hymo; NR-11LS) 0.02 parts

<Base paper formulation 2>
Base paper formulation; LBKP (freeness: 320 ml, csf) 85 parts
NBKP (freeness: 480 ml, csf) 15 parts calcium carbonate (Okutama Kogyo Co., Ltd .; TP-121) 15 parts ASA sizing agent (Hoshiko Chemical Co., Ltd .; Colopearl Z-100) 0.03 parts aluminum sulfate 0.6 part amphoteric starch (manufactured by NSC Japan; Cato 3210) 1 part Yield improver (manufactured by Hymo Company; NR-11LS) 0.02 part

<Base paper composition 3>
Base paper formulation; LBKP (freeness: 320 ml, csf) 85 parts
NBKP (freeness: 480 ml, csf) 15 parts calcium carbonate (Okutama Kogyo Co., Ltd .; TP-121) 15 parts Neutral rosin sizing agent (Harima Kasei Co., Ltd .; NeuSize M-10-45) 0. 4 parts Aluminum sulfate 1.2 parts Amphoteric starch (NSC, Japan; Cato3210) 1 part Yield improver (Himo, NR-11LS) 0.03 parts

<Base paper formulation 4>
Base paper formulation; LBKP (freeness: 320 ml, csf) 85 parts
NBKP (freeness; 480 ml, csf) 15 parts talc (manufactured by Hyogo Clay; Hyogo talc) 15 parts rosin sizing agent (manufactured by Arakawa Chemical Industries; size pine N-705) 0.4 parts aluminum sulfate 2.5 parts synthetic paper strength agent (manufactured by Seiko Chemical Industry Co., Ltd .; Stargum A-15) 0.8 parts Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 parts

<Base paper formulation 5>
Base paper formulation; LBKP (freeness: 320 ml, csf) 85 parts
NBKP (freeness: 480 ml, csf) 15 parts Indonesia clay (manufactured by PT ALTER ABADI; BRU-30) 15 parts rosin sizing agent (manufactured by Arakawa Chemical Industries; size pine N-705) 0 .4 parts Aluminum sulfate 3 parts Synthetic paper strength agent (manufactured by Seiko Chemical Industry Co., Ltd .; Stargum A-15) 0.8 part Yield improver (manufactured by Hymo Co., Ltd .; NR-11LS) 0.02 part

<Base paper composition 6>
Base paper formulation: LBKP (freeness: 320 ml, csf) 50 parts
NBKP (freeness: 480 ml, csf) 15 parts
Imitation waste paper pulp (freeness: 200 ml, csf) 35 parts calcium carbonate (Okutama Kogyo Co., Ltd .; TP-121) 12 parts AKD sizing agent (Arakawa Chemical Co., Ltd .; SPK-903) 0.04 parts sulfuric acid Aluminum 0.8 part amphoteric starch (manufactured by NSC Japan; Cato 3210) 1 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

<Base paper formulation 7>
Base paper formulation; LBKP (freeness: 320 ml, csf) 55 parts
NBKP (freeness: 480 ml, csf) 15 parts
Forest certified LBKP (freeness: 340 ml, csf) 30 parts calcium carbonate (Okutama Kogyo Co., Ltd .; TP-121) 12 parts AKD sizing agent (Arakawa Chemical Co., Ltd .; SPK-903) 0.03 parts sulfuric acid Aluminum 0.8 part amphoteric starch (manufactured by NSC Japan; Cato 3210) 1 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

<Base paper formulation 8>
Base paper formulation: NBKP (freeness: 480 ml, csf) 15 parts
Imitation waste paper pulp (freeness: 200 ml, csf) 35 parts
Forest certified LBKP (freeness: 340 ml, csf) 50 parts calcium carbonate (Okutama Kogyo Co., Ltd .; TP-121) 12 parts AKD sizing agent (Arakawa Chemical Co., Ltd .; SPK-903) 0.04 parts sulfuric acid Aluminum 0.8 part amphoteric starch (manufactured by NSC Japan; Cato 3210) 1 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

<Base compound 9>
Base paper formulation: NBKP (freeness: 480 ml, csf) 15 parts
Imitation waste paper pulp (freeness: 200 ml, csf) 35 parts
Forest certified LBKP (freeness: 340 ml, csf) 50 parts talc (Hyogo Clay; Hyogo talc) 12 parts rosin sizing agent (Arakawa Chemical Industries; size pine N-705) 0.4 parts Aluminum sulfate 2.5 parts Synthetic paper strength agent (manufactured by Seiko Chemical Industry Co., Ltd .; Stargum A-15) 0.8 part Yield improver (manufactured by Hymo Co .; NR-11LS) 0.02 part

A 0.3% slurry of each of the above-mentioned base paper blends was made 1,300 mm in width, 300 m / min in paper making speed, 300 vibrations / minute in shaking, 13 mm in amplitude (shaking strength 47), and a J / W ratio of 1.030. A base paper having a basis weight of 67.7 g / m ² and a water content of 3.0% was produced using a long paper machine under the conditions described above.

The base paper 1 produced above was subjected to an inked two-roll size press using the composition of the size press liquid 1 to obtain a base paper having a solid content of 2 g / m ^2. The coated base paper used for the craft paper was used. The aspect ratio of the tensile strength of the base paper 1 was 1.24. Furthermore, for the coating base paper used for the produced offset rotary printing coated paper, 65% by mass of a coating liquid containing the following pigment coating liquid was applied to a coating amount of 14 g / m ² on one side using a blade coater, Double-sided coating was performed at a coating speed of 1,200 m / min.

<1 size press solution>
Oxidized starch (Nippon Food Processing Co., Ltd .; MS-3800) 5 parts Water 95 parts

<1 pigment coating solution>
Commercial first grade kaolin clay 50 parts Commercial heavy calcium carbonate 50 parts Commercial polyacrylic acid dispersant 0.1 parts Latex binder 12 parts Commercial phosphate starch 3 parts Commercial carboxymethylcellulose thickener (CMC) 0.1 parts Hydroxide Sodium adjusted to pH 9.6

  It was produced in the same manner as in Example 1 except that a paper web was formed at a shaking frequency of 350 times / min and an amplitude of 13.5 mm (shaking strength of 64) in the paper making process. The aspect ratio of the tensile strength of this base paper was 1.22.

  It was produced in the same manner as in Example 1 except that a paper web was formed at a shaking frequency of 390 times / min and an amplitude of 13.0 mm (shaking strength 79) in the paper making process. The aspect ratio of the tensile strength of this base paper was 1.19.

  It was manufactured in the same manner as in Example 1 except that the base paper composition 1 was changed to 2 in the papermaking process. The aspect ratio of the tensile strength of this base paper was 1.24.

  It was manufactured in the same manner as in Example 1 except that the base paper composition 1 was changed to 3 in the papermaking process. The aspect ratio of the tensile strength of this base paper was 1.24.

  It was manufactured in the same manner as in Example 1 except that the base paper composition 1 was changed to 4 in the papermaking process. The aspect ratio of the tensile strength of this base paper was 1.25.

  It was manufactured in the same manner as in Example 1 except that the base paper composition 1 was changed to 5 in the papermaking process. The aspect ratio of the tensile strength of this base paper was 1.25.

  It was manufactured in the same manner as in Example 1 except that the base paper composition 1 was changed to 6 in the papermaking process. The aspect ratio of the tensile strength of this base paper was 1.23.

  It was manufactured in the same manner as in Example 1 except that the base paper composition 1 was changed to 7 in the paper making process. The aspect ratio of the tensile strength of this base paper was 1.23.

  It was produced in the same manner as in Example 1 except that the base paper composition 1 was changed to 8 in the papermaking process. The aspect ratio of the tensile strength of this base paper was 1.22.

  It was manufactured in the same manner as in Example 1 except that the base paper composition 1 was changed to 9 in the papermaking process. The aspect ratio of the tensile strength of this base paper was 1.23.

  In the paper making process, the basis weight profile in the width direction is not controlled by the pulp slurry in the base paper composition 1, and the basis weight profile control in the width direction is performed by increasing or decreasing the conventional lip opening, and without using the shaking. It was manufactured in the same manner as in Example 1 except that the J / W ratio was changed to 1.002. The aspect ratio of the tensile strength of this base paper was 1.28.

  It was manufactured in the same manner as in Example 1 except that the J / W ratio was changed to 1.008 in the base paper formulation 1 in the paper making process. The aspect ratio of the tensile strength of this base paper was 1.20.

(Comparative Example 1)
Example 1 except that in the paper making process, a paper web was formed by changing the J / W ratio to 1.062 at a shaking frequency of 200 times / minute, an amplitude of 6.0 mm (shaking strength of 9.6), and a J / W ratio of 1.062. Produced in the same way. The aspect ratio of the tensile strength of this base paper was 2.18.

(Comparative Example 2)
It was manufactured in the same manner as in Comparative Example 1 except that the J / W ratio was changed to 1.030 in the paper making process. The aspect ratio of the tensile strength of this base paper was 1.32.

(Comparative Example 3)
It was manufactured in the same manner as in Example 12 except that the J / W ratio was changed to 1.030 in the paper making process. The aspect ratio of the tensile strength of this base paper was 1.52.

  The evaluation result will be described.

  In the papermaking process in Examples 1 to 11 and Comparative Examples 1 to 3, the use of shaking and the aspect ratio of the tensile strength of the base paper by J / W ratio control, the wrinkles and the texture in the coated paper for offset rotary printing are as follows: The measurement results are shown in Table 1, and the evaluation results are shown in Table 1.

<Aspect ratio of tensile strength>
About each base paper, the tensile strength of the vertical direction and the horizontal direction of the base paper was calculated | required according to JISP-8113. In addition, when using shaking, the data changes depending on the sampling position of the base paper. Therefore, the CD machine direction is divided into 7 parts for the entire width of the paper machine, and the MD direction is divided into 14 samples of 4 m samples. The average value of the data was used.

<Hijiwa>
Using an offset rotary printing press (Mitsubishi Heavy Industries, Ltd., Lithopia BT-2-600), printing ink for rotary offset printing (Dainippon Ink, Web World Terrace N, black, indigo, red, yellow The wrinkles in the flow direction of the solid print portion were visually evaluated. The evaluation of Hijiwa was written as follows. A: Almost not generated, O: Slightly generated, Δ: Occurred, x: Significantly generated.

<Guide>
3D Sheet Analyzer Model made by M / K Systems M / K 950 total (using glass optical drum (thickness 2.29 mm, thickness variation 0.14 mm or less)) Was measured. The spot area at the time of measurement is 0.44 m ² (spot diameter is about 0.75 mm), and the measurement area is 10 cm × 10 cm. The greater the formation index, the better the formation. In Table 1, ◎: formation index is 40 or more, formation is very good, ○: formation index is less than 40, formation is good, 25: formation index is less than 25, formation is poor. .

[Evaluation results]
As described above, according to Table 1, by controlling the aspect ratio of the tensile strength of the base paper within a predetermined range, the wrinkles generated during drying after printing of the offset rotary coated coated paper can be reduced. It can be reduced and the texture of the coated paper can be satisfied at the same time. Furthermore, no difference was observed between the acid papers of Examples 6 and 7 and the neutral papers of Examples 1 to 5, and the wrinkles were reduced in the waste paper-mixed base paper of Example 8 and the forest certified material LBKP-mixed base paper of Example 9. It can be seen that Furthermore, it turns out that the elbow is further improved in Examples 10 and 11 in which these pulps are combined. On the other hand, when the aspect ratio of the tensile strength is large as in Comparative Example 1, the effect of reducing elbows is not manifested, and it is understood that the offset rotation of the pulp fiber can disturb the formation if it is not the optimum value even if it is tried to match with the J / W ratio. When drying after printing. Example 12 is a papermaking condition that does not use shaking, but the aspect ratio can be in a good range by setting the J / W ratio to an optimum value. On the other hand, in the comparative example 3, since the J / W ratio is deviated from the optimum value, the aspect ratio is out of the favorable range, and the wrinkles are also deteriorated.

  It can be applied as a coating base paper used for offset rotary printing coated paper.

Claims (4)

In a coated base paper used for offset rotary printing coated paper provided with at least one coating layer on one side or both sides, the aspect ratio of the tensile strength of the base paper is 1.1 to 1.3. Coated base paper used for coated paper for rotary printing. The coated base paper used for the offset rotary printing coated paper according to claim 1, wherein the coated base paper is made of LBKP, a forest certified material, as a pulp raw material. The coated base paper used for the offset rotary printing coated paper according to claim 1, wherein the coated base paper is made of waste paper pulp as a pulp raw material. In the manufacturing method of the coating base paper used for the coated paper for offset rotary printing of any one of the said Claims 1-3, by the control means of J / W ratio independent, or the combination with the control means of shaking. A method for producing a coated base paper for use in coated paper for offset rotary printing, characterized in that it is produced.